Locking mechanism for self-propelled tandem axle trailer

ABSTRACT

A trailer for towing by a power vehicle is provided and generally includes a frame and a tandem wheel assembly. The trailer is provided with a drive assembly having a locking mechanism to selectively engage the drive from the motor to the wheels of the trailer. The locking mechanism having a reciprocating pushing member that may push an urging member to act upon a flanged driveshaft to selectively engage a clutch of the drive assembly.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of Ser. No. 16/599,820 filedon Oct. 11, 2019, which claims the benefit of the filing date ofProvisional Patent Application No. 62/744,901, filed on Oct. 12, 2018.

FIELD OF THE INVENTION

The invention relates to a self-propelled tandem axle trailer and, moreparticularly, to a self-propelled tandem axle trailer having a rearextending storage bin and a movable front axle.

BACKGROUND

Workers often find that providing materials for replacement of abuilding roof is very time consuming, considering the task involvesusing different mechanical units or manual labor to lift buildingmaterials from a truck and position them on a roof. Furthermore,stripping old material from the building roof in order to put on a newroof is also time consuming and a dirty job. Generally, old material isthrown from the roof to the ground around the building and then workersmanually pick up debris to deposit it into a disposal container. Even ifthe material can be thrown directly into a container there remain theproblems of getting the disposal container in proximity to the roof andremoval from the work site. The most common solution to the disposalproblem is to move a dump truck adjacent to the building and to attemptto throw the material directly from the roof into the truck bin.Furthermore, the problem is not limited to roofing material. Anybuilding remodeling generates significant construction trash, and themost convenient method of removing it from the building is to throw itout a window.

As a result, it is not always possible to move a large truck into alocation adjacent to a building. Fences, lawns, and shrubs can bedamaged by any size truck, especially a large transport truck.

There is a need for a vehicle that can move around the typicallandscaped yard surrounding a building and position a storage bin intoan extended position near workers and that is study enough to handlelarge loads.

SUMMARY

In view of the foregoing, a trailer for towing by a power vehicle isprovided and generally includes a frame and a tandem wheel assembly. Theframe forms an undercarriage chassis which the tandem wheel assembly ispositioned there under. The undercarriage chassis includes a rear wheelassembly, a front wheel assembly, and an extension assembly moving thefront wheel assembly between trailing position and a self-propelledposition where the rear wheel assembly and the front wheel assembly arepositioned to equally support the undercarriage chassis.

In an exemplary embodiment, there may be provided a locking mechanismfor selectively engaging a drive assembly of a self-propelled trailer,the locking mechanism having: a pushing member having a sliding seal,and a detent, the pushing member configured to reciprocate between afirst position and second position; a pushing member receptacleconfigured to receive the pushing member, and providing a fixed seal andfirst and second ports; an urging member secured at one end by a pivotpin, and having a roller capable of at least partially residing withinthe detent of the pushing member while in the second position, theroller secured to the urging member; the urging member being normallybiased in a first direction, and moved in a second direction by thepushing member, such that the roller resides at least partially withinthe detent, while the urging member is pushed in the second direction,the urging member having a free end configured to urge a lateralmovement of a flanged driveshaft to disengage a clutch of the driveassembly, while the urging member is moved in a second direction.

In an exemplary embodiment, the pushing member may be hydraulicallyactuated, and each of the first and second ports of the pushing memberreceptacle are hydraulic ports. The first port may be in fluidcommunication with the pushing member above the sliding seal of thepushing member. The second port may be in fluid communication with thepushing member below the sliding seal of the pushing member, and abovethe fixed seal of the pushing member receptacle. The introduction offluid through the first port may create a fluid pressure that causes thepushing member to move from the first position to the second position.In an exemplary embodiment, the removal of the fluid pressure does notcause the pushing member to move from the second position to the firstposition. In an exemplary embodiment, the introduction of fluid throughthe second port may cause the pushing member to move from the secondposition to the first position.

In an embodiment, the drive assembly further comprises a motor,transmission, and the driveshaft is slidably extended between thetransmission and the clutch. The motor may be reversible and may be oneof a hydraulic motor, a pneumatic motor, and an electric motor.

In an exemplary embodiment, there is provided a trailer for towing by apower vehicle, having: a frame forming an undercarriage chassis; atandem wheel assembly positioned under the undercarriage chassis andhaving a rear wheel assembly and a front wheel assembly, each of thefront and rear wheel assemblies comprising a wheel assembly frame, andfirst and second hub assemblies, each comprising a drive assemblyincluding a motor, transmission, driveshaft, selectively engageableclutch and locking mechanism, and a hub; and an extension assemblymoving the front wheel assembly between trailing position and aself-propelled position where the rear wheel assembly and the frontwheel assembly are positioned to equally support the undercarriagechassis.

In an exemplary embodiment, the locking mechanism has a pushing memberhaving a sliding seal, and a detent, the pushing member configured toreciprocate between a first position and second position; a pushingmember receptacle configured to receive the pushing member, andproviding a fixed seal and first and second ports; an urging membersecured at one end by a pivot pin, and having a roller capable of atleast partially residing within the detent of the pushing member whilein the second position, the roller secured to the urging member; theurging member being normally biased in a first direction, and moved in asecond direction by the pushing member, such that the roller resides atleast partially within the detent, while the urging member is pushed inthe second direction, the urging member having a free end capable ofurging a lateral movement of the driveshaft so as to disengage a clutchof the drive assembly, while the urging member is moved in a seconddirection.

In an exemplary embodiment, the pushing member may be hydraulicallyoperated, and each of the first and second ports may be hydraulic ports,the first port being in fluid communication with the pushing memberabove the sliding seal, and the second port being in fluid communicationwith the pushing member below the sliding seal and above the fixed seal.The introduction of fluid through the first port may create a fluidpressure that causes the pushing member to move from the first positionto the second position. In an exemplary embodiment, the removal of thefluid pressure does not cause the pushing member to move from the secondposition to the first position, as the roller at least partiallyresiding within the detent of the pushing member maintains the pushingmember in the second position. In an exemplary embodiment, theintroduction of fluid through the second port may cause the pushingmember to move from the second position to the first position, andremove the roller from residing within the detent.

In an exemplary embodiment, the selectively engageable clutch comprisesa positive clutch including a driving clutch element having a pluralityof teeth, and a reversible driven clutch element having a keyed firstsurface, and a recessed second surface, wherein, when the reversibledriven clutch element is in a first orientation, and the clutch isengaged, the plurality of teeth of the driving clutch element arepositively engaged with the keyed first surface of the driven clutchelement for causing the rotation of the hub by the motor.

In an exemplary embodiment, the motor is configured for rotation ineither direction, and is one of hydraulic motor, pneumatic motor, andelectric motor. The transmission may be a planetary gear reduction unitto accept an input torque from the motor, and deliver an output torqueto the driveshaft that is different from the input torque. In anexemplary embodiment, the planetary gear reduction unit delivers anoutput torque to the driveshaft that is a value that is higher than thevalue of the input torque to the driveshaft.

In an exemplary embodiment, the frame includes a plurality of supportbeams including a support rail and positioned and secured apart by aplurality of connecting beams, a front support, a rear support. In anexemplary embodiment, each of the front and rear wheel assembly framesinclude a body with a pair of low friction guides positioned at oppositeside ends thereof and corresponding to the support rail of each of theplurality of support beams. Each of the low friction guides may be au-shaped member including low frictions pads to provide a low frictioncoefficient between the front wheel frame and the support rail.

In an exemplary embodiment, each of the rear wheel assembly and frontwheel assembly may further comprise a steering assembly.

In an exemplary embodiment, the trailer may further comprise a storagebin and an extension device connected to the frame and the storage binto move the storage bin away from the frame.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in greater detail below with reference toembodiments and the appended drawings of which:

FIG. 1 is a front perspective view of a self-propelled tandem axletrailer according to the invention,

FIG. 2 is rear perspective view of the self-propelled tandem axletrailer of FIG. 1;

FIG. 3 is perspective view of a self-propelled tandem axle traileraccording to the invention, showing extension of a front axle to adrivable position;

FIG. 4 is another perspective view of the trailer of FIG. 3, showingextension and inclination of a storage bin thereof;

FIG. 5 is a front perspective view of the trailer of FIG. 3, showingfurther extension and inclination of the storage bin;

FIG. 6 is a rear perspective view of the trailer of FIG. 5;

FIG. 7 is a close up view of a front wheel of the self-propelled tandemaxle trailer according to the invention;

FIG. 8 is a bottom perspective view of the self-propelled tandem axletrailer according to the invention;

FIG. 9A is a bottom perspective view of another embodiment of theself-propelled tandem axle trailer according to the invention;

FIG. 9B is a bottom view of the self-propelled tandem axle trailer ofFIG. 9A;

FIG. 10 is a perspective front partial view of an alternative embodimentof a front wheel assembly of the self-propelled tandem axle traileraccording to the invention;

FIG. 11A is a close up, rear view of a suspension, drive and hubassembly of the self-propelled tandem axle trailer according to theinvention;

FIG. 11B is cross-section view of the suspension components of FIG. 11A;

FIG. 12A is a partially exploded view of components of the driveassembly and hub assembly, including flanged driveshaft, clutchassembly, locking mechanism, and hub;

FIG. 12B is a partially exploded view of components of the driveassembly and hub assembly, including a bell housing, hub, and torsionarm;

FIG. 13A is a top view of an alternative embodiment of a wheel assemblyof the self-propelled tandem axle trailer according to the invention;

FIG. 13B is a bottom view of an alternative embodiment of a wheelassembly of the self-propelled tandem axle trailer according to theinvention;

FIG. 14 is a partially exploded view of components of the wheel hubassembly depicting the motor, transmission, torsion arm, brake assemblyand hub;

FIG. 15 is a cross-section view of components of the wheel hub assembly;

FIG. 16A is close up view of the clutch assembly, depicting the drivingand driven clutch elements;

FIG. 16B is a cross-section view through the engaged clutch elements,depicting the teeth of each of the driving clutch element against theteeth of the driven clutch element;

FIG. 17 depicts a close up, cross-section view of the locking mechanismand driveshaft

FIG. 18 depicts an exploded view of the locking mechanism elements andbell housing.

DETAILED DESCRIPTION OF THE EMBODIMENT(S)

With respect to FIGS. 1-6, a trailer 1 according to the invention isshown and ready for towing by a power vehicle, such as a truck with atow hitch. The trailer 1 generally includes the following majorcomponents: a frame 10, a control system 60, a storage bin 80, and anextension device 100, and a tandem wheel assembly 300.

Now with reference to FIGS. 1-4, the frame 10 will be discussed. In theshown embodiment, the frame 10 includes a plurality of support beams 12,a plurality of connecting beams 14, a front support 16, a rear support18, a trailer connection section 22.

As shown in FIGS. 2 and 3, each support beam 12 is an elongated metalsupport extending along a length of the frame 10, from a trailing end toa leading end thereof.

In the embodiment shown, each support beam 12 is I-shaped and includes asupport rail 13 positioned on a lower end and running along a lengththereof.

Each connection beam 14 runs substantially perpendicular and connectingto the plurality of support beams 12. The front support 16 is a platelike member connecting the support beams 12 at a front end thereof,while the rear support is another plat like member connecting thesupport beams 12 at an opposite end thereof. As assembled, the supportbeams 12, connection beams 14, front support 16, and rear support form aundercarriage chassis 20

As shown, in an exemplary embodiment of the invention, the trailerconnection section 22 is a trailer hitch 22 positioned and connected toa leading end of the frame 10, and, in particular, the front support 16.The trailer hitch 22 includes a connector for connecting with a truck(i.e., ball mount; not shown).

According to the invention, the trailer 1 includes a tandem wheelassembly 300. In an exemplary embodiment of the invention, the tandemwheel assembly 300 is positioned under the undercarriage chassis 20 andgenerally includes a rear wheel assembly 310, a front wheel assembly340, and an extension assembly 380.

As shown in FIG. 8, the rear wheel assembly 310 includes a pair of rearwheels 312, a rear wheel frame 314, a rear steering assembly 320, and arear drive assembly 330.

In the embodiment shown, the rear wheel frame 314 includes a rear guidemember 315 member having a body 316 and a pair of low friction guides318 positioned at opposite side ends thereof. Each low friction guide318 is a u-shaped member secured to the rear wheel frame 314 and issized and shaped to correspond to receive the support rail 13. The lowfriction guide 318 includes low frictions pads 319 are bearing padsknown in the art to provide a low friction coefficient between the rearwheel frame 314 and the support rail 13. In the shown embodiment, thelow friction pads 319 line an inside surface of the low friction guide318.

In the embodiment shown, the rear wheel assembly 310 includes steeringcapability using a rear steering assembly 320 according to theinvention. However, one skilled in the art should appreciate that thisrear wheels 312 may be non-steerable. As shown, the rear steeringassembly includes a steering bracket 322, a pair of steering arms 324connected to the steering bracket 322 and the pair of rear wheels 312.

As shown in FIG. 8, in an exemplary embodiment of the invention, therear wheel assembly 310 includes a rear drive assembly 330 according tothe invention. In an exemplary embodiment of the invention, the reardrive assembly 330 includes a hydraulic motor assembly 332 and a rotorassembly 334, and an engagement assembly 370 for each rear wheel 312.

In an embodiment of the invention, the hydraulic motor assembly 332generally includes a motor 332 a, a motor drive mechanism 332 b, and amotor housing 332 c. The motor 332 a is connected to the control system60 using hydraulic lines (not shown). The motor 332 a is attached to theoutside of the motor housing 332 c. The motor drive mechanism 332 bpositioned in a motor housing 332 c is engageable with the hydraulicmotor 332 a and moveable by the engagement assembly 370.

In an embodiment of the invention, the rotor assembly 334 includes awheel hub 334 a and a drive shaft 334 b with a rotor drive mechanism(not shown) engageable with the motor drive mechanism 332 b by theengagement assembly 370. The drive shaft 334 b connected to the wheelhub 334 a.

Many of the power system components are not shown for sake of complexityin the drawings, although a discussion is provided for purposes ofenabling one skilled in the art to understand how the drive system isassembled and performed. One skilled in art should appreciate that otherdesigns are possible. For instance, the rear drive assembly 330 mayinclude other methods to move the rear wheels 312, including chains,belts, or a drive shaft and a transmission connected to a combustion orelectric engine, so that trailer 1 can be moved around a work site underits own power.

As shown in FIGS. 7 and 8, the front wheel assembly 340 includes a pairof front wheels 342, a front wheel frame 344, a front steering 350assembly, and a front drive assembly 360.

In the embodiment shown, the front wheel frame 344 is u-shaped memberhaving a body 346 and a pair of low friction guides 348 positioned atopposite side ends thereof. Each low friction guide 348 is a u-shapedmember secured to the front wheel frame 344 and is sized and shaped tocorrespond to receive the support rail 13. The low friction guide 348includes low frictions pads 349 that are bearing pads known in the artto provide a low friction coefficient between the front wheel frame 344and the support rail 13. In the shown embodiment, the low friction pads349 line an inside surface of the low friction guide 318.

In the embodiment shown, the front wheel assembly 340 includes steeringcapability using a front steering assembly 350 according to theinvention. However, one skilled in the art should appreciate that thisfront wheels 342 may be non-steerable. As shown, the front steeringassembly includes a steering bracket 352, a pair of steering arms 354connected to the steering bracket 352 and the pair of front wheels 342.

As shown in FIG. 8, in an exemplary embodiment of the invention, thefront wheel assembly 340 includes a front drive assembly 360 accordingto the invention. However, one skilled in the art should appreciate thatthese front wheels 342 may be non-driveable, without a drive system.

In an exemplary embodiment of the invention, the front drive assembly360 generally includes a hydraulic motor assembly 362 and a rotorassembly 364, and an engagement assembly 370 for each front wheel 342.

In an embodiment of the invention, the motor assembly 362 generallyincludes a motor 362 a, a motor drive mechanism 362 b, and a motorhousing 362 c. The motor 362 a is connected to the control system 60using hydraulic lines (not shown). The motor 362 a is attached to theoutside of the motor housing 362 c. The motor drive mechanism 362 bpositioned in a motor housing 362 c is engageable with the hydraulicmotor 362 a and moveable by the engagement assembly 370.

In an embodiment of the invention, the rotor assembly 364 includes awheel hub 364 a and a drive shaft 364 b with a rotor drive mechanism(not shown) engageable with the motor drive mechanism 362 b by theengagement assembly 370. The drive shaft 364 b connected to the wheelhub 364 a.

Many of the power system components are not shown for sake of complexityin the drawings, although a discussion is provided for purposes ofenabling one skilled in the art to understand how the drive system isassembled and performed. One skilled in art should appreciate that otherdesigns are possible. For instance, the front drive assembly 360 mayinclude other methods to move the front wheels 342, including chains,belts, or a drive shaft and a transmission connected to a combustion orelectric engine, so that trailer 1 can be moved around a work site underits own power.

In the shown embodiment, the rear wheel assembly 310 and the front wheelassembly 340 includes an engagement assembly 370. As shown, eachengagement assembly 370 generally includes a main shaft 372, a firstlever assembly 374, and a second lever assembly 376. The main shaft 372is an elongated cylindrical member and connected to the first leverassembly 374 and the second lever assembly 376 at opposite ends thereof.The first lever assembly 374 and the second lever assembly 376 areconnected to opposite rear wheels 312 or front wheel 342, and engage anddisengage the motor drive mechanism 332 b, 362 b, from the rotor drivemechanism (not shown) to rotate the wheel hub 334 a, 364 a.

In an exemplary embodiment of the invention, the extension assembly 380generally includes a rear end connector 382, a moveable axle connector384, and a moving component 386. The rear end connector 382 is connectedto the rear wheel assembly 310, while the moveable axle connector 384 isconnected to the front wheel assembly 340. The moving component 386 is ahydraulic actuator positioned and secure to the undercarriage chassis 20in the shown embodiment. The moving component 386 is capable ofextension and contraction. When connected to the front wheel assembly340, the front wheels 342 can be positioned between the trailingposition A (see FIGS. 1 and 2) and the self-propelled position B (seeFIGS. 5-8).

FIGS. 9A and 9B depict an alternate exemplary embodiment of theinvention. The trailer 1′ of FIGS. 9A and 9B generally includes thefollowing major components: a frame 10, a control system 60, a storagebin 80, and an extension device 100, as discussed previously, and analternate tandem wheel assembly 300′. Though not depicted in FIGS. 9A orB, it is contemplated that the trailer 1′ would beneficially include asource of power, similar to the example power source depicted in FIGS.1-6, and 8, and may, in exemplary embodiments, be one or more ofbatteries and/or combustion engines. The power source may power orotherwise enable the powered movement and actions of the variousfeatures of the trailer described herein, including power forself-propelled transport, steering, braking, extension and/or retractionof the tandem wheel assembly, and movement of the storage bin, relativeto the frame.

As shown in FIG. 9A, the alternate tandem wheel assembly 300′ ispositioned under the frame 10, and generally includes a rear wheelassembly 310′, a front wheel assembly 340′, and an extension assembly380′. As described previously, the tandem wheel assembly provides for afront wheel assembly that is movably secured to the support rails 13,such that the front wheel assembly can selectively be positioned in thetrailing position A (seen with reference to FIGS. 1 and 2), and theself-propelled position B, depicted in FIG. 9A, or any interveningposition between them.

In any of the trailer embodiments, the front wheel assembly 340′ mayoptionally be secured in either, or both, of the position A or B, by anactuatable locking mechanism, such as a manually or mechanically engagedlocking mechanism, for example, locking pins, and the like, that securethe wheel assembly and frame elements so as to prevent unwanted movementrelative to each other. Alternatively, the front wheel assembly may bemaintained in the desired position through the actuation mechanism, forexample, maintaining hydraulic pressure in a hydraulic actuator tosecure the front wheel assembly in the desired position, such as whentravelling, trailering, or parked and at rest.

FIG. 9A depicts the rear wheel assembly 310′ having a pair of rearwheels 312, mounted to the hubs of the wheel assembly. Further aspectsof a wheel assembly are discussed below. In an embodiment, the rearwheel assembly 310′ may be fixedly secured in a position relative to theframe; for example, the rear wheel assembly may be immovably secured tothe support rails 13. The rear wheel assembly may be affixed or securedusing techniques known to those skilled in the art. For example, therear wheel assembly may be mounted to the frame 10 or support rails 13through the use of one or more fasteners, including for example,mounting posts, bolts and/or nuts, to secure the wheel assembly to thesupport rails or other frame portion; or alternatively, a portion of therear wheel assembly may be welded to the support rails 13 or otherportion of the frame 10.

Also depicted in FIG. 9A is a front wheel assembly 340′, having a pairof wheels 342, mounted on hubs of the front wheel assembly. In anembodiment, the front wheel assembly is movably mounted upon the frame10 of the trailer; for example, by the use one or more u-shaped membersslidably mounted on the front wheel frame, where the u-shaped member issized and shaped to receive at least a portion of the support rail 13 ofthe frame, as depicted in FIGS. 9 and 10. The u-shaped member may beprovided with low friction guide elements 348, including low frictionpads 349 that serve as bearing pads known in the art to provide a lowfriction coefficient between the front wheel frame 344′ and the supportrail 13. In this manner, the front wheel assembly is movably secured tothe frame in a manner that allows the wheel assembly to slide upon theframe support rails, and be alternately positioned in a trailer positionA (depicted in FIG. 1), and the self-propelled position B as depicted inFIG. 9, or any point in between. As can be seen in the exemplaryembodiment of FIG. 10, the front wheel assembly 340′ is provided withu-shaped members slidably mounted on separate, parallel support rails 13on the frame 10, and are positioned such that the u-shaped membersprevent twisting movement of the front wheel assembly, relative to theframe, as the spacing provided between the inside dimensions of theopposing u-shaped members is substantially the same, or nearly the same,as the maximum width dimension of the support rails 13.

In an exemplary embodiment of the invention, as depicted in FIG. 9A, theextension assembly 380 generally includes a fixed end connector 382′that may be affixed to the frame at or near the rear support plate 18,though it is contemplated that alternatively, the connector 382′ may besecured to the rear wheel assembly, which is itself fixed relative tothe frame. The extension assembly 380 further provides a moveable axleconnector 384′, and a moving component 386′. The fixed end connector382′, as depicted in FIG. 9A may be directed through a bracket openingon the rear wheel assembly 310′, and affixed to the rear support plate18 of the frame 10. The fixed end connector 382′ may alternatively besecured to the frame 10 at any point rearward of the front axle when intrailering position A of FIG. 1, so as the extension assembly isextended, the forward axle assembly is urged away from the fixationpoint on the frame. Though not shown, it is contemplated that theextension assembly may be configured in the reverse orientation (notdepicted), where an extension assembly is alternatively secured to theframe at a mounting point forward of the front axle when in position Bof FIG. 3, where extension of the extension assembly urges the frontaxle rearward into position A for trailering, and retraction of theextension assembly urges the front axle to position B for self-propelledmovement of the trailer.

In an embodiment, as depicted in FIG. 9A, the fixed end connector 382′near the rear of the trailer may be the end portion of a linear actuatorof the extension assembly 380′, which may fit into a bracket and securedin place against the rear support plate 18 of the frame 10. Theextension assembly 380′ further provides for a moveable axle connector384′ on the front wheel assembly 340′. In an embodiment, the front wheelassembly 340′ may have a bracket that secures to a portion of the linearactuator of the extension assembly 380′ and serves as the moveable axleconnector 384′, as depicted in FIG. 9A. The moving component 386′ may beany suitable form of linear actuator, for example, a hydraulic actuatorpositioned and secured to the undercarriage chassis 20, or frame 10′.The moving component 386′ is capable of extension and contraction. In anembodiment, the moving component 386′ is a double acting hydrauliccylinder. In an embodiment, the front wheel assembly 340′ is secured toa portion of the cylinder barrel of the hydraulic cylinder, and thepiston rod is secured to the rear of the frame. It is contemplated thatwhere the moving component is a hydraulic cylinder, the positioning ofthe cylinder components may be mounted in reverse, with the piston rodaffixed to the front wheel assembly, and the cylinder barrel secured toframe 10 closer to the rear of the trailer 1′, or alternatively,directly connected to the rear wheel assembly 310′. It is contemplated,that in any mounting configuration where the linear actuator isconnected to the front wheel assembly 340′, the front wheel assembly340′ can selectively be positioned between the trailing position A (seeFIGS. 1 and 2) and the self-propelled position B (see FIGS. 9A and B),by the action of the linear actuator.

Details of the front wheel assembly 340′ and rear wheel assembly 310′will now be discussed with reference to FIGS. 10 and 13A and B. Forsimplicity, the front wheel assembly 340′ will be described, thoughapplicable to the features of the rear wheel assembly 310′ as well. Anisolated front wheel assembly 340′ is depicted in FIG. 10 in frontperspective view. FIG. 13A presents a top view of the isolated wheelassembly, with the u-shaped brackets removed for clarity. FIG. 13Bpresents a bottom view of the isolated wheel assembly. It is anticipatedthat the depicted wheel assembly in FIGS. 10 and 13 may be deployed asone or both of the front wheel assembly or rear wheel assembly.

For simplicity, FIG. 10 will be described in the context of being afront wheel assembly 340′, though applicable to either front or rearwheel assembly. With reference to FIG. 10, the front wheel assembly 340′as shown may be provided with a wheel assembly frame 344′, a steeringassembly 350′, and a pair of hub assemblies 402.

Each hub assembly 402 includes a drive assembly 404, a suspensionassembly 406, brake assembly 408, and hub 410 upon which a wheel is tobe mounted. The front wheel assembly 340′ of FIG. 10 may providesteering capability, motive and braking force to the trailer 1′, as wellas serving as a suspension, to isolate or minimize the effects ofirregular surface features from the frame while the trailer is inmotion. The front wheel assembly 340′ of FIGS. 10, 13A, and 13B howeverfeatures marked differences from those wheel assemblies describedpreviously; for example, each wheel assembly is provided with a singlesteering actuator, rather than two steering arms as previouslydescribed, resulting in a simpler, more cost effective design, whereeach wheel of the wheel assembly is maintained at a consistent angle,relative to the other wheel of the wheel assembly through the use of amechanical linkage, such as a tie rod, extended between each hubassembly to ensure each hub assembly's steering angle consistent withthe other.

As can be seen with reference to FIGS. 10 and 13A and B, exemplary frontwheel assembly 340′ in the depicted embodiment may include a pair ofhubs configured to accept the mounting of wheels thereupon, with thewheels removed for clarity, a drive assembly, a brake assembly 408, awheel assembly frame, a steering assembly, and suspension assembly. Thewheel assembly of FIGS. 10 and 13A, B may be deployed as either, orboth, of the front and rear wheel assemblies. It is contemplated thatone of the wheel assembly embodiment depicted in FIG. 10 may be combinedwith a different embodiment of a wheel assembly, for example, the wheelassembly described previously with reference to FIG. 8.

In an embodiment, the wheel assembly frame 344 may provide support formounting the other wheel assembly components from, and may be, forexample, a truss or beam extended between the aforementioned u-shapedguide elements 348 configured to slide upon the frame rails 13.

The wheel assembly embodiment 340′, as can be seen with reference toFIGS. 13A and 13B provides a steering capability through the action of asteering assembly 350′ according to the invention. As depicted, thesteering assembly 350′ includes a steering bracket 322′ which may beaffixed to, or otherwise be made as part of the wheel assembly frame, asteering arm 324′ (depicted in FIG. 13) extended between the steeringbracket 322′ and a steering arm mount 412 on a primary hub assembly. Thesteering assembly further comprises a tie rod 414 extended betweensteering knuckles 416 on each of the hub assemblies, which may besecured via a balljoint to allow for suspension movement.

As was noted previously, either or both of the front and rear wheelassemblies may independently provide steering capabilities to thetrailer 1′. It is contemplated that the trailer 1′ of FIG. 9A mayselectively employ rear wheel steering, front wheel steering, or 4-wheelsteering. It is contemplated that in order to minimize the turningradius, the extension assembly may be adjusted to be less than fullyextended (so that the front wheel assembly is at a point betweenposition A and position B, in order to shorten the wheelbase by movingthe front wheel assembly in a direction towards the middle of thetrailer, and thereby reduce the turning radius of the trailer,especially when employing round steer mode of four wheel steering. Inthis circumstance, the center of gravity for the trailer should remainwithin the dimensions defined by the axles, so as to avoid disruptingthe balance of the trailer.

Each hub assembly for each of the wheel assemblies for the trailer 1′may have a brake assembly 408 including a brake caliper and brake rotor,as can be seen with reference to FIG. 10, by which the rotation of thewheels on the wheel assembly may be selectively slowed, or stopped fromrotation. The brake assembly 408 may be actuated hydraulically,electrically, pneumatically, or mechanically. It is contemplated thatany of the brake assemblies may be actuated independently, so as to slowor prevent the rotation of any single wheel, or alternatively, the brakeassemblies may be actuated in pairs (fronts or rears) together, orfurther, the brake assemblies may be actuated all together, so as toprovide four wheel braking, or prevent rotation of all four wheelssimultaneously. It is contemplated that one or more of the brakeassemblies may be actuated to secure the trailer 1′ in a desiredposition, acting as a parking brake. In an alternative embodiment, it iscontemplated that alternative braking solutions are possible, using, forexample, drum brakes as are well understood, or alternatively, using ahydraulic drive system (discussed below), which may provide brakingforce for the trailer, whether as a supplement to the disk brake systempreviously described, or as a replacement, such that the hydraulic motormay function as the brake system for the trailer, obviating the need fora disk and caliper brake system, where the hydraulic motor system isemployed to provide fluid resistance to the rotation of the wheel andhub, thereby providing braking or locking of the wheel and hub fromrotation.

Each of the hub assemblies may have a suspension assembly, such as atorsion suspension depicted in FIGS. 11A and B, that allows theindependent movement of the wheel hub, relative to the wheel assemblyframe, and the trailer it is affixed to, as the trailer traverses unevenground.

In an exemplary embodiment, and with reference to FIG. 14, each of thehub assemblies of the trailer may include a drive assembly that isconfigured to selectively transmit a motive force through the driveassembly to cause the hub 410, and thus a wheel mounted upon the hub toturn, thereby propelling the trailer 1′. As can be seen with referenceto the partially exploded view provided by FIG. 14, a motor 470 may beprovided, which may be a hydraulic motor as depicted, though it iscontemplated that the motor may instead be any suitable motor, includingelectric or pneumatic, which when actuated will result in the rotationof the motor output shaft 472 in a selectable direction. In anembodiment, the drive and direction of rotation of the motor 470 foreach of the hub assemblies are independently, selectively reversible, soas to provide adequate maneuverability to the trailer 1′ and minimizethe turning radius. The rotatable motor output shaft 472 is directedinto an input opening in a transmission housing 460, which may contain agear reduction system, for example, a planetary gear set which serves toincrease the torque output from the motor, while reducing speed ofrotation. The output from the transmission housing 460 is directed to aflanged driveshaft 474, as will be discussed.

As shown in FIG. 12A, the wheel assembly may be provided with aselectively engageable clutch assembly 500, providing a mechanismallowing each wheel of a wheel assembly to be driven by the motor, or toallow the hub/wheel to free-wheel independently of any rotation of thedriveshaft. While the clutch is engaged, motive forces provided by themotor 470 are directed through the transmission 460, if any, and then bythe driveshaft 474, whereby the motive forces may be passed through theclutch mechanism 500 to cause the rotation of the hub assembly uponwhich the wheel is mounted, thereby driving the wheel. While the clutch500 is disengaged, the wheel and hub assembly may spin freely,independent of the driveshaft 474 and motor 470, as may be requiredwhile the trailer 1′ is being towed by a powered vehicle betweenlocations. The clutch mechanism 500 may be of any suitable type forselectively transmitting torque from the motor to the wheel, as isunderstood by those skilled in the art, and may include friction,centrifugal, diaphragm, positive, hydraulic, electromagnetic, or vacuumclutches, as non-limiting examples.

As can be seen with reference to FIGS. 15, 16A and 16B, the clutchassembly 500 will be engaged or disengaged with the lateral shifting ofthe flanged driveshaft 474. While the driveshaft is in the firstposition, the teeth of the driving clutch element 502 will be engagedwith the receiving elements (such as teeth) of the driven clutch element504, in order to positively transmit the rotation of the flangeddriveshaft 474 through the clutch 500 elements and to the wheel hub 410.While the flanged driveshaft 474 is in the second position, the teeth ofthe driving clutch element 502 will not be engaged with the receivingelements of the driven clutch element 504, as the lateral shift of thedriveshaft 474 is enough to separate the driving clutch element 502 fromthe driven clutch element 504. Thus, so long as the driveshaft 474remains in the second position, the driveshaft 474 may be caused torotate by the motor, and the driving clutch element 502 will alsorotate, yet there as there is no contact between the driving clutchelement 502 and the driven clutch element 504, then the driven clutchelement 504, wheel hub 410 and wheel will remain isolated from movementof the driveshaft and motor, if any; moreover, while the trailer 1′ isbeing towed, the driven clutch element 504, wheel hub 410 and wheel willbe free to turn, without affecting the driveshaft 474 and motor 470.

To actuate the lateral movement of the flanged driveshaft 474 in orderto engage and disengage the clutch, the wheel hub assembly may beprovided with a locking mechanism 600, which may be any suitableactuation, including manual, electric, hydraulic, or pneumaticoperation. In the exemplary embodiment depicted in FIG. 15, and ingreater detail in FIG. 17, the locking mechanism 600 provides ahydraulic actuator, and comprises at least one of each of a pushingmember 602 and one or more seals 604 configured to slidingly reciprocatewithin a pushing member receptacle 603, an urging member 606, a roller608, and a pivot pin 610, which may be fitted within the confines of thepushing member receptacle. The seals 604 may be O-rings that are mountedon the body of the pushing member, and may partially resided withinO-ring grooves on the pushing member. An exploded view of the componentsof the locking mechanism 600 is depicted in FIG. 18, depicting thelocking mechanism as a cartridge component that may be fitted into thebell housing 476. As depicted, the pushing member receptacle 603 may bea hollow body, that is configured to slidably accept the pushing membertherein, and acts similar to a hydraulic cylinder barrel, in that it isconfigured to contain hydraulic pressure acting upon the pushing member602, which acts as a hydraulic cylinder. The pushing member receptaclemay be provided with a fixed seal 605, which may be a gland seal ormechanical seal, such as an O-ring, positioned in the pushing memberreceptacle below the seals on the pushing member, where the fixed sealreceives the elongate body portion of the pushing member therethrough,and serves to prevent leakage of hydraulic fluid below the fixed seal.The urging member 606 is secured at one end over a pivot pin 610, and isfree to move laterally at the other end. The urging member 606 isnormally biased in a direction away from the motor (to the left asdepicted in FIG. 15), which may be accomplished using any suitablemethod, for example, with a spring pushing against the urging member,normally biasing to the left in FIG. 15. When the pushing member 602 issubjected to hydraulic pressure, such as may be applied through thefirst hydraulic port 612, the pressure above the pushing member seal 604is increased, and causes the pushing member 602 to be advanced towardsthe driveshaft 474 (in a downward direction), whereupon the lowerportion of the pushing member 602 encounters the roller 608, which issecured to the urging member 606, typically near the mid-point of theurging member. Further advancement of the pushing member 602 causes theroller 608, to be displaced, depicted in a direction to the right inFIGS. 15 and 17, whereupon the urging member 606 will pivot upon thepivot pin 610 securing the end of the urging member, as a fulcrum end.The movement at the free end of the urging member 606 will be magnifiedby the lever arrangement of the urging member, such that the free end ofthe urging member is moved to the right and encounters a flange 475 ofthe driveshaft 474, and thus urges the driveshaft to the right, into thesecond position of the driveshaft, thereby retracting the teeth of thedriving clutch element 502 so as to not be engaged with the drivenclutch element 504.

In an embodiment, the pushing member 602 may have a detent 616 thataligns with the roller when the pushing member is advanced downwards.The detent may be in the form of an indentation on the surface of thepushing member 602, that is sized to accommodate at least a portion ofthe roller 608, so that the roller is received within the indentation.The roller 608, while it is at least partially received within thedetent 616, provides resistance to the pushing member returning to theraised position, and maintains the pushing member in the down position,even in the absence of hydraulic pressure at the first port 612. In thismanner, the hydraulic system may be depressurized (as may be preferredfor towing the trailer between locations), and as the pushing member 602will remain advanced downward, the urging member 606 will continue tourge the driveshaft 474 to remain in the second position, ensuring theclutch 500 will remain disengaged. Thus, with the clutch disengaged, thetrailer 1′ may be towed as the hub 410 can free-wheel, without theclutch 500 elements being engaged, and without causing unwanted movementof the motor 470 and transmission 460 components.

Reversal may be accomplished by removing the hydraulic pressure at thefirst port 612, and increasing the hydraulic pressure through the secondhydraulic port 614, which increases the pressure below the seal 604 onthe pushing member 602, and above the fixed seal 605. The increasedpressure from below the seal 604 of the pushing member 602 will overcomethe holding force from the roller 608 residing against the detent 616,and drive the pushing member 602 upwards, away from the driveshaft 474as the roller 608 leaves the detent 616, and continued movement of thepushing member 602 upwards will free the roller 608 from encounteringthe pushing member at all, such that the urging member 606, along withthe roller 608 may pivot upon the fulcrum of the pivot pin 610 andreturns to the initial position, whereby the driveshaft 474 is no longerurged to the second position, and can revert to the first position. Withthe driveshaft no longer urged away from the motor, the clutch 500becomes engaged as the teeth of the driving clutch element 502 anddriven clutch element 504 become engaged, so that the trailer 1′ may beself-propelled by rotation of one or more motors 470.

In an embodiment, it is contemplated that the driven clutch element 504of FIG. 16A may be reversible, so as to present the recessed surfacetowards the driving clutch element 502. When reversed in this manner,the clutch 500 will be disengaged, regardless of the position of thedriveshaft 474, such that the hub 410 will free-wheel, though remainssubject to braking application, as previously described. In this manner,one wheel hub assembly drive may be disabled, as may be necessary in theevent of a malfunction, or equipment breakage. Reversal of the drivenclutch element 504 is accomplished by removing the fasteners securingthe driven clutch element 504, and replacing it with the normallyexterior facing recessed surface (as can be seen in FIG. 12A) directedinwards.

Now with reference to the Figures, the control system 60 will bediscussed and generally includes a power system source (i.e. combustionengine, battery) and a control assembly connected (hydraulic andelectrical lines) to the rear wheel assembly 310, the front wheelassembly 340, and the extension assembly 380.

Regardless of the specific mode of powering the rear wheels 312, thecontrol system 60 controls starting, stopping and turning the rearwheels 312, as well as for regulating the speed of the rear wheels 312.Likewise, the control system 60 also controls starting, stopping andturning the front wheels 342, as well as for regulating the speed of thefront wheels 342.

The control system 60 includes a plurality of controls which may be aseries of buttons, levers, or other suitable controls which allow theoperator to control expansion and retraction of the front wheel assembly340 using the extension assembly.

In an embodiment, user controls may be provided on the control system 60for controlling certain other features of the trailer 1. As shown in theembodiment of FIG. 1, an operator stand may sit in operator's box 62,allowing an operator to move along with the trailer 1 as the operatorcontrols the trailer 1 movement. The control system 60 thereforeprovides the operator with the ability to control all features of thetrailer 1 from a single location, while standing on the operator standand moving along with the trailer 1 as the trailer 1 travels under itsown power.

In a trailing position A, the front wheels 342 are positioned adjacentto the rear wheels 312, while in the self-propelled position B the frontwheels 342 are positioned to equally support the undercarriage chassis20 and, more particularly, the storage bin 80.

According to the invention, the front wheels 342 are positioned betweenthe trailing position A and the self-propelled position B by theextension assembly 380.

Now with reference to FIGS. 1-4, the storage bin 80 generally includes aplatform 82, a plurality of retaining walls 84, a tailgate 90, and apair of cover sections 94.

The platform 82 includes a planar section extending substantiallyparallel with the frame 10. In the shown embodiment, the platform 82 isa rectangular metal plate. However, one skilled in the art shouldappreciate that the platform 82 could be manufactured using differentshapes and other materials, such as lumber, composite, and other metals.For instance, the platform 82 may include a framed metal structure onwhich a plurality of wood planks are arranged.

The plurality of retaining walls 84 includes a pair of side retainingwalls 86 and a retaining end wall 88. In the shown embodiment, eachretaining wall 84 is metal plate. However, one skilled in the art shouldappreciate that each retaining wall 84 could be manufactured using othermaterials, such as lumber, composite, and other metals. For instance,each retaining wall 84 may include a framed metal structure on which aplurality of wood planks is disposed along the framed metal structure.

The plurality of retaining walls 84 is positioned and secured alongouter edges of the platform 82 and, in particular, along a top planarsurface thereof. In the shown embodiment, the pair of side retainingwalls 86 are positioned along opposite longitudinal sides of theplatform 82, while the retaining end wall 88 is positioned at trailingend of the platform 82. Each retaining wall 84 extends substantiallyperpendicular with respect to the top planar surface of the platform 82.Each retaining wall 84 is mechanically secured to the platform 82, forinstance, using a weld or plurality of known mechanical fasteners. Inaddition, the retaining end wall 88 is secured to a pair of common endsof the side retaining walls 86. In the embodiment shown, the retainingend wall 88 is mechanically secured to the pair of side retaining walls86, for instance, using a weld or other known mechanical fasteners oradhesives.

As shown, the tailgate 90 is positioned along a leading end of theplatform 82, opposite the retaining end wall 88 positioned along thetrailing end thereof. In the embodiment shown, the tailgate 90 is madeof a metal. However, one skilled in the art should appreciate that thetailgate 90 could be manufactured using other materials, such as lumber,composite, and other metals. For instance, tailgate 90 may include aframed metal structure on which a plurality of wood planks is disposedalong the framed metal structure.

As shown, the tailgate 90 is positioned along an outer edge of theplatform 82 and extends substantially perpendicular to the top planarsurface thereof. The tailgate 90 is secured to the platform 82, forinstance, through a rotating fastener device, such as a rotating hinge92 positioned at bottom of the tailgate 90 and connecting to theplatform 82. The rotating hinge 92 permits rotation of the tailgate 90from a secured closed vertical position to one in which the tailgate 90rotates away from the retaining end wall 88 making the platform 82accessible. However, one skilled in the art should appreciate that otherdesign are possible. For instance, the tailgate 90 may be pivotablymounted to side retaining walls 86 such that the tailgate 90 pivots awayfrom the outer edge of the platform 82 or from the side retaining walls86, much like known dump trucks.

Each cover section 94 is a rectangular metal structure having a planarsurface. Each cover section 94 is positioned along and connected toupper outer edges of the pair of side retaining walls 86 using aplurality of hinges 96. However, one skilled in the art shouldappreciate that other designs are possible. For instance, other knownrotating mechanisms could be used. Each cover section 94 measuresapproximately half a width as measured between the pair of sideretaining walls 86.

A pair of stops 98 are provided and positioned along a common side atopposite ends of the cover section 94. In particular, each stop 98 isdisposed along an outer edge of the cover section 94 that is proximateto the side retaining wall 86 when assembled. Each stop 98 is a metalplate having one end secured to the cover section 94. In an exemplaryembodiment, the stop 98 is semi-circle shaped having a free endconfigured to abut the side retaining wall 86 when the cover section 94rotates about the hinge 96. The stop 98 configuration determines thatangle at which the cover section 94 is positioned in an open position.For instance, if the stop 98 has a 135 degree semi-circle shape, thenthe cover section 94 will be positioned at a 45 degree angle withrespect to a plane extending across top surfaces of both side retainingwalls 86.

In the shown embodiment, a plurality of wall supports 99 are providedand disposed along outer surfaces of the platform 82, the retainingwalls 84, the tailgate 90, and the cover sections 94. The wall supports99 provide reinforcement for the planar surfaces of each of the outersurfaces. In the shown embodiment, each wall support 89 is a tubularstructure of metal that is mechanically secured to the outer surfaces,for instance, using a weld. However, one skilled in the art shouldappreciate that other known fastening means are possible, including butnot limited to screws, nuts and bolts, and adhesives.

Now with references to FIGS. 4-6 and 8, the extension device 100according to the invention will be described. As shown, the extensiondevice 100 includes the following major components: a first extensionsection 102, a second extension section 120, and a storage bin platformsection 180.

As shown, the first extension section 102 is shown and generallyincludes a pair of lower supports 104 reciprocally connected to thesupport beams 12 and a lower lifting actuator assembly 106 connected tothe front support 16.

Each lower support 104 is an elongated structural support and, in theshown embodiment, a metal plate. Each lower support 104 includes aplurality of fastener receiving through-holes 108 positioned at atrailing end, leading end, and a middle section thereof. The pair oflower supports 104 are positioned parallel, and are rotatably secured tothe frame 10 using fasteners. The lower lifting actuator assembly 106includes a pair of hydraulic actuators connecting to the front support16 at one end and to the middle section of the lower support 104 atanother end thereof using fasteners.

As shown, the second extension section 120 is shown and includes a boomsupport 122, a sliding support 124, a sliding mechanism 130, an upperlifting actuator assembly 140, and an articulating arm assembly 150.

The boom support 122 is elongated structural beams and, in the shownembodiment, a tubular metal beam. The boom support 122 includes a pairof fastener receiving brackets 123 with through holes positioned at atrailing end thereof and extending completely there through.

As shown, each sliding support 124 is an elongated structural beamshaving a boom support receiving passageway 126 opening from a trailingend thereof and extending there through a body of sliding support 124.The boom support receiving passageway 126 is shaped to receive the boomsupport 122 and, as shown, a cross section area of the boom supportreceiving passageway 126 is larger than a cross section area of the boomsupport 122. As a result, a leading end of the boom support 122 ispositioned through the boom support receiving passageway 126.

In the shown embodiment, each sliding support 124 is a tubular metalbeam. Each sliding support 124 includes a fastener receivingthrough-hole 128 positioned at a leading end thereof and extendingcompletely there through.

The sliding mechanism 130 is positioned between and connected to theboom support 122 and the boom support receiving passageway 126.

Each sliding mechanism 130 includes an actuator section 132 which may bea known hydraulic cylinder having a barrel, a piston, piston rod, seals,and seal glands. However, one skilled in the art should appreciate thatother actuator systems operated by a source of energy, such as electriccurrent, hydraulic fluid pressure, or pneumatic pressure.

In the shown embodiment, the upper lifting actuator assembly 140includes a pair of hydraulic actuators 142 is positioned between frame10 and the second extension section 120. Each hydraulic actuators 142includes an actuator 174 which may be a known hydraulic cylinder havinga barrel, a piston, piston rod, seals, and seal glands. However, oneskilled in the art should appreciate that other actuator systemsoperated by a source of energy, such as electric current, hydraulicfluid pressure, or pneumatic pressure.

As shown, in an exemplary embodiment of the invention, the articulatingarm assembly 150 is a pair of plate like members (see FIG. 8) rotatablyconnected to the sliding support 124 and the storage bin 180 using thestorage bin platform section

As shown, the storage bin platform section 180 is shown and generallyincludes a platform 182, a platform cross member 184, a tilting actuatorcross member (not shown), and a pair of bin tilting actuators (notshown).

Now with reference to FIGS. 1, 10, and 11, operation of the trailer 1 or1′ according to the invention will be described.

Building materials can be loaded and secured in the storage bin 80 at alocation different than the work site. A truck (not shown) connects tothe frame 10 using the trailer hitch 22. The operator positioned thefront wheel assembly 340 apart from the rear wheel assembly 310 usingthe extension assembly 380. The front wheel assembly 340 and the rearwheel assembly 310 are set to drive and steer using the control system60. The trailer 1 or 1′ then can operate as a standard trailer and betowed behind the connected truck to the work site.

The operator then uses the control system 60 to move the trailer 1 or 1′to a desired location on the work site using the drive system of thefront wheel assembly 340 and the rear wheel assembly 310, as describedabove. The operator may now use the control system 60 to stabilize thetrailer 1 or 1′.

Once the operator has determined that the trailer 1 is in position tounload building materials from the storage bin 80, the operator canmanage the stabilizers (not shown), as known and well understood bythose skilled in the art, to stabilize and level the trailer 1 or 1′.The operator then uses the control system 60 to control the extensiondevice 100 and position of the storage bin 80.

The operator can use the control system 60 to control the vertical andhorizontal position of the storage bin 80. In addition, the operator canslide the storage bin 80 horizontally with respect to frame 10.

The foregoing illustrates some of the possibilities for practicing theinvention. Many other embodiments and fields of use for the trailer 1 or1′ are possible and within the scope and spirit of the invention. It is,therefore, intended that the foregoing description be regarded asillustrative rather than limiting.

What is claimed is:
 1. A locking mechanism for selectively engaging adrive assembly of a self-propelled trailer, the locking mechanismcomprising: a pushing member having a sliding seal, and a detent, thepushing member configured to reciprocate between a first position andsecond position; a pushing member receptacle configured to receive thepushing member, and providing a fixed seal and first and second ports;an urging member secured at one end by a pivot pin, and having a rollercapable of at least partially residing within the detent of the pushingmember while in the second position, the roller secured to the urgingmember; the urging member being normally biased in a first direction,and moved in a second direction by the pushing member, such that theroller resides at least partially within the detent, while the urgingmember is pushed in the second direction, the urging member having afree end configured to urge a lateral movement of a flanged driveshaftto disengage a clutch of the drive assembly, while the urging member ismoved in a second direction.
 2. The locking mechanism of claim 1,wherein pushing member is hydraulically actuated, and each of the firstand second ports of the pushing member receptacle are hydraulic ports.3. The locking mechanism of claim 2, wherein the first port is in fluidcommunication with the pushing member above the sliding seal of thepushing member.
 4. The locking mechanism of claim 3, wherein the secondport is in fluid communication with the pushing member below the slidingseal of the pushing member, and above the fixed seal of the pushingmember receptacle.
 5. The locking mechanism of claim 4, whereinintroduction of fluid through the first port creates a fluid pressurethat causes the pushing member to move from the first position to thesecond position.
 6. The locking mechanism of claim 5, wherein theremoval of the fluid pressure does not cause the pushing member to movefrom the second position to the first position.
 7. The locking mechanismof claim 5, wherein introduction of fluid through the second port causesthe pushing member to move from the second position to the firstposition.
 8. The locking mechanism of claim 1, wherein the driveassembly further comprises a motor, transmission, and the driveshaft isslidably extended between the transmission and the clutch.
 9. Thelocking mechanism of claim 8, wherein the motor is reversible and is oneof a hydraulic motor, a pneumatic motor, and an electric motor.
 10. Atrailer for towing by a power vehicle, comprising: a frame forming anundercarriage chassis; a tandem wheel assembly positioned under theundercarriage chassis and having a rear wheel assembly and a front wheelassembly, each of the front and rear wheel assemblies comprising a wheelassembly frame, and first and second hub assemblies, each comprising adrive assembly including a motor, transmission, driveshaft, selectivelyengageable clutch and locking mechanism, and a hub; and an extensionassembly moving the front wheel assembly between trailing position and aself-propelled position where the rear wheel assembly and the frontwheel assembly are positioned to equally support the undercarriagechassis.
 11. The trailer of claim 10, wherein the locking mechanismcomprises a pushing member having a sliding seal, and a detent, thepushing member configured to reciprocate between a first position andsecond position; a pushing member receptacle configured to receive thepushing member, and providing a fixed seal and first and second ports;an urging member secured at one end by a pivot pin, and having a rollercapable of at least partially residing within the detent of the pushingmember while in the second position, the roller secured to the urgingmember; the urging member being normally biased in a first direction,and moved in a second direction by the pushing member, such that theroller resides at least partially within the detent, while the urgingmember is pushed in the second direction, the urging member having afree end capable of urging a lateral movement of the driveshaft so as todisengage a clutch of the drive assembly, while the urging member ismoved in a second direction.
 12. The trailer of claim 11, wherein thepushing member is hydraulically operated, and each of the first andsecond ports are hydraulic ports, the first port being in fluidcommunication with the pushing member above the sliding seal, and thesecond port being in fluid communication with the pushing member belowthe sliding seal and above the fixed seal.
 13. The trailer of claim 12,wherein introduction of fluid through the first port creates a fluidpressure that causes the pushing member to move from the first positionto the second position.
 14. The trailer of claim 13, wherein removal ofthe fluid pressure does not cause the pushing member to move from thesecond position to the first position, as the roller at least partiallyresiding within the detent of the pushing member maintains the pushingmember in the second position.
 15. The trailer of claim 14, whereinintroduction of fluid through the second port causes the pushing memberto move from the second position to the first position, and removes theroller from residing within the detent.
 16. The trailer of claim 10,wherein the selectively engageable clutch comprises a positive clutchincluding a driving clutch element having a plurality of teeth, and areversible driven clutch element having a keyed first surface, and arecessed second surface, wherein, when the reversible driven clutchelement is in a first orientation, and the clutch is engaged, theplurality of teeth of the driving clutch element are positively engagedwith the keyed first surface of the driven clutch element for causingthe rotation of the hub by the motor.
 17. The trailer of claim 10,wherein the motor is configured for rotation in either direction, and isone of hydraulic motor, pneumatic motor, and electric motor.
 18. Thetrailer of claim 10, wherein the transmission is a planetary gearreduction unit to accept an input torque from the motor, and deliver anoutput torque to the driveshaft that is different from the input torque.19. The trailer of claim 10, wherein the frame includes a plurality ofsupport beams including a support rail and positioned and secured apartby a plurality of connecting beams, a front support, a rear support. 20.The trailer of claim 19, wherein each of the front and rear wheelassembly frames include a body with a pair of low friction guidespositioned at opposite side ends thereof and corresponding to thesupport rail of each of the plurality of support beams.
 21. The trailerof claim 20, wherein each low friction guide of the pair of low frictionguides is a u-shaped member includes low frictions pads to provide a lowfriction coefficient between the front wheel frame and the support rail.22. The trailer of claim 10, wherein each of the rear wheel assembly andfront wheel assembly further comprise a steering assembly.
 23. Thetrailer of claim 10, further comprising a storage bin and an extensiondevice connected to the frame and the storage bin to move the storagebin away from the frame.